There has been known a fuel injection device including a control body, which has a pressure control chamber, and a valve member for opening and closing a valve portion in response to the pressure of fuel in the pressure control chamber. In the fuel injection device, the pressure control chamber of the control body has an inflow port and an outflow port opened therein. The inflow port is a port through which fuel flowing through a supply channel flows into the pressure control chamber, and the outflow port is a port through which the fuel is discharged to a return channel. The pressure of the fuel in the pressure control chamber is controlled by a pressure control valve for making communication between the outflow port and the return channel and for interrupting the communication between them.
In a fuel injection device disclosed in patent document 1 (JP 6-108948A corresponding to U.S. Pat. No. 4,826,080), a pressing member is further provided in a pressure control chamber, to be reciprocally displaced in the pressure control chamber. When the outflow port is made to communicate with the return channel by the pressure control valve, the pressing member is drawn to the opening wall surface having the outflow port opened therein by a reduce of the fuel pressure near the outflow port, thereby pressing the opening wall surface by the pressing member. When the opening wall surface is pressed by the pressing member, the pressing member interrupts the communication between the inflow port and the pressure control chamber, and the outflow port. In addition, when the pressure control valve interrupts the outflow port and the return channel, the pressing member is pressed by the high-pressure supply fuel supplied from the supply channel via the inflow port, and displaces in a direction separated from the opening wall surface. By the displacement of the pressing member, the inflow port and the pressure control chamber are made to communicate with each other.